This invention relates generally to a folder apparatus for folding sheet material, and more particularly concerns a sheet folder with a fold path transverse to a feed path.
In the field of sheet material handling, folders are well known. Oftentimes, it is desirable to place one or more folds in a sheet or a plurality of sheets. Typically, the sheets may be made of paper, plastic, fabric or some other material. Folders have been developed to automate the folding process and thus obtain operational efficiencies over manual methods which tend to be labor intensive, costly and slow. There are various methods of generating folds in paper. These include buckle folding, knife folding, pinch folding and plow folding. In the mail preparation field, buckle chute folders and knife folders are well known.
Typically, a buckle chute folder comprises two or more fold rollers operating in cooperation with one or more buckle chutes and deflectors to place a sequence of folds in one or more sheets. A conventional buckle chute also includes a stop which is adjustably positioned within the chute for folding the sheets at a particular dimension or distance from the leading edge of the sheet. In operation, a first pair of rollers feeds a stack of sheets (or a single sheet) into the first buckle chute. When the leading edge of the stack hits the stop in the chute, forward progress of the stack ceases. However, the first pair of rollers continues to feed the stack causing a buckle to form in a predetermined location along the length of the stack near the entrance to the buckle chute. As the buckle grows, it enters the nip between another pair of rollers which are positioned adjacent the predetermined location. These rollers fold the stack along the buckle and feed the stack out of the buckle chute. This process is then repeated in subsequent downstream buckle chutes to produce more than one fold in the stack. Thus the feed path can have a long footprint.
Typical buckle chute folders 1, as shown in FIG. 1a, function by driving a sheet S along an input feed path F with drive rollers 3, 5 through a fold chamber 7 against a stop 9, and allowing a controlled buckle to form within an appropriately designed set of baffles. This buckle is drawn into a nip by a pair of fold rollers 3, 6. These rollers usually contact the sheet along most of its width and have a high normal force to insure a tight fold. Typically, knife folders 1a, as shown in FIG. 1b, work by registering one or more sheets S adjacent a pair of fold rollers 2, 4 by contacting an edge of the sheet S against a stop 9 and deflecting the sheet S into a fold nip using a moving knife edge bar 8 which is moved in the direction A as shown in FIG. 1b. 
Another type of folder is a plow folder. Plow folders use long curved form guides to gradually fold a form as the form is fed widthwise along the guide. The fold is completed by feeding the form through a set of rollers. Plow folders are typically quite long as compared to the more compact design of the buckle chute or knife folders. Typical plow folders which are typically used in web folding apparatus and have a longer footprint than buckle chute or knife folders.
Folders are typically used in conjunction with mail processing systems which automatically insert folded sheets into envelopes. Common types of sheet folds are C-folds, Z-folds shown in FIGS. 1c and 1d, respectively. With the C-fold, sheets are folded twice as shown in FIG. 1c. With the Z-fold, sheets are folded twice in a Z configuration as shown in FIG. 1d. A Z-fold is commonly used when an address is desired to be indicated through the window of a window envelope (not shown).
Prior paper folding apparatus operate using complicated systems of rollers, paper stops and multiple paper path direction reversals to create each sheet fold separately. Typically the above described folders also rely on rapidly forcing the sheet through pinch rollers to create folds. These complex apparatus require greater manufacturing assembly and maintenance costs. Also, they result in high noise and vibration, and limited speed at which sheets can be folded and processed due to the serial nature of creating the folds. These systems also have an abundance of moving and stationary parts.
Thus there is a need for a folder which substantially overcomes the disadvantages and drawbacks associated with the prior art folders. Particularly, there is a need for folder to provide less noise, compact design and the ability to create folds substantially simultaneously. There is also a need for a folder with reduced manufacturing assembly and maintenance costs.
This invention overcomes the disadvantages of prior art folders by providing a folder which has a fold path transverse to a feed path. The folder overcomes disadvantages of other folders by creating multiple folds substantially simultaneously. Additional advantages include reduced noise and vibration and a smaller footprint.
This invention relates generally to a folder apparatus for folding sheet material, and more particularly concerns a folder with a fold path transverse to a feed path. In an embodiment of the present invention, the folder comprises a channel or sheet guide for receiving and/or guiding a sheet, feed rollers for feeding the sheet along the feed path and through the channel, the feed rollers are axially aligned with the feed path, guide rollers positioned transverse to the feed path for feeding the sheet along a fold path to pinch rollers which pinch the sheet to form folds. The paper path does not reverse and the folding action is smooth so that noise and vibration are reduced. Also, the folder has a smaller footprint than prior art plow folders.
An advantage of the present invention is that it provides folder that has a smaller footprint than prior art plow folders. Another additional advantage of the present invention is that the folder creates less noise and vibration than buckle chute or knife folders. Another advantage is that multiple folds can be created substantially simultaneously. Other advantages of the invention will in part be obvious and will in part be apparent from the specification. The aforementioned advantages are illustrative of the advantages of the various embodiments of the present invention.